Chalcone compounds are a generic term for compounds having a chalcone backbone having the following formula (Ka 1). As these compounds, various compounds obtained by extraction or synthesis from natural products have been known.

In addition, there are a variety of physiological activities of these compounds, depending upon the compounds. For example, cytotoxicity, anticancer activity, chemoprotectant property, anti-mutagenesity, antibacterial activity, antiviral activity, antiprotozoal property, insecticidal action and the like have been known (for example, Non-Patent Publication 1). In addition, the present inventors have found that these chalcone compounds have enhancing actions for nerve growth factor (NGF) production (for example, Patent Publication 1).    Patent Publication 1: WO 01/54682    Non-Patent Publication 1: J. R. Dimmock and three others, Current Medicinal Chemistry (the Netherlands), 1999, 6, 1125-1149